Compensated dynamo-electric machine.



L. TORDA.

- COMPENSATED DYNAMO ELECTRIC INE. APPLICATION PiLED r3129, 1

1,053,680. I Patented Feb. 913.

VViinesses: V: Inventor, 5. 9%. I4 40%- f L. TORDA.

GOMPENSATED DYNAMO ELECTRIC MACHINE APPLICATION FILED rmmo, 190s.

2 SHEETS-6113B? 2.

Patented Feb. 18, 1913.

in excess of UNITED STATES T-UDWIG TOBDA,

0F WILKIN SBUBG, PENNSYLVANIA.

COMPENSATED DYNAJIO -ELECTBIC MACHINE.

Specification of LettersPatent.

Patented Feb. 18, 1913.

Application filed February 29, 1908. Serial No. 418,533.

To all whom it may concern:

Be it known that I, LUDWIG TOBDA, a resident of Wilkinsbur in the county of Allegheny and State 0 Pennsylvania, have invented certain new and useful Improvements in Compensated Dynamo-Electric Machines, of which the following is a specification.

This invention relates to dynamo electric machines with commutators for direct and alternating current, and has particular reference to so-called compensated machines.

Com ensated machines hitherto constructe are characterized by the fact that along the whole inner periphery of the stationary part of such a machine grooves'or slots parallel to the armature slots are provided. Embedded in these slots are coils forming a winding, which iscalled compensating winding because its magnetomotive-force is compensating the armature magneto-motive-force. The compensating winding is uniformly distributed and is so arranged that compensating coils are embracing each space whichseparates two adjacent main poles. The mam disadvantage of such a compensated machine is that it is too expensive for most practical purposes, the amount of copper required for the compensating winding being to 100% the amount required for the armature winding. The loss of energy in the compensating winding is correspond ingly large and thereby the efliciency of the machine-is impaired. Another economical disadvantage of the compensated machines, heretofore built is that, owing to the fact that the'whole inner periphery of the magnet frame or the whole of the pole faces are occupied by the compensating winding, its construction is not sufliciently simple.

The object of this invention is to re the cost, increase the etticiencyv and simplify the construction of compensated machines. This purpose is attained by so arranging a compensating winding that it covers only a portion of the inner peri hery of the stationary part, with its coi s embracing only duce ' alternate main pole-separating spaces, and

by suitably shaping the main ole faces.

With machines subject to t is invention a considerable saving is efiected both in copper and in energy,- and owing to the compensating winding embracing only alternate field-magnet separating s aces, the stationary part can be built in in epcndent and may be disassembled without first taking out the armature, or removing any of the compensating coils.

The principle underlying. this improved construction 16, that the field distortion is reduced or eliminated withoutv compensating the whole armature magneto-motivefor'ce. Accordingly, machines embodying this principle may briefly be. called semicompensated machines. In semi-compensated machines the airgap between the arma ture and magnet frame can be reduced to the mechanically admissible minimum, thereby diminishing the main field ampere turns and proportionately diminishing the amount of main-field copper required, and reducing the loss of energy to a minimum. This result had heretofore not been attained in other than fully com nsated machines. In a semi-compensated machine wherein a commutating field is required to obtain good commutation, I prefer to provide the sections,

device known as a commutating pole, placed in each main-pole-separating space brldged by a compensating coil. In some cases commutating poles may be placed in each space between a jacent main p0 es, those commutating poles not embrace by the compensating windings each having its own energizing coil. v

The invention. may be variously embodied in both directand alternating current machines, three adaptations thereof to direct current machines being shown. in the accompanying drawings, wherein- Figure 1 is a view partly in elevation and partly in section of a desirable embodiment of the invention, and Fig. 2 is an inner edge .view of one of the main frame sections and the parts carried thereby. Figs. 3 and 5 are views similar to Fig. 1 of other adaptations of the invention, and Figs. 4 and 6 are vertical cross sections. taken, respectively, on lines 4-7-4 and ti -6 0i Figs. 3 and-5; Fig. 6 is a detail, showin the term and construction of the art illustrated in Figs. 5 and 6 which carrles the compensating winding. Fig. 7 is a diagram of the connections of the windings.

Referring to Figs. 1 and 2 of the drawings, the stationary magnet frame A supoition E embracin having a central commutating pole ,projecting from me is compensating winding D,

A'midway between magnets B, the outer portion E of the winding extending to a portion only of each pole face of the adjacent magnets B, the face portions thus reached by the winding being slotted at J to receive the same. The slotted port-ion G of the pole faces that receive the winding are in the form of detachable members, with screws G securing them to the magnets. Adjacent members G are united by the connecting brackets H of non-magnetic material, extending from one to the other at opposite sides of commutating pole F. Laterally open cavities or recesses K in brackets H receive and support the central portions E of the compensating winding, and the outer portion E extends through the slots J in face member G as shown. The lain portion L of each pole face may al o be detachable and secured to the body of the magnet by screw L. Attention is directed to the shape of the face of this unslotted portion. At the side thereof next to the slotted face G, the clearance or airgap between it and the rotating part W of the machine is substantially the same as at the slotted portion, all as indicated at M. Beyond this and to the outer end or side of member L, the face diverges from the rotating member, as shown at M. This increase in the airgap causes the reluctance of the magnetic path to be substantially the same at the non-slotted'portion of the pole face as at the slotted port1on,tl1us preventing an unequal distribution of the main field along the pole face. Also, this increase in the airgap reduces further the field distortion. @ne of the structural advantages of this arrangement is that the slotted pole faces and the auxiliary winding may be adjusted with reference to each other and secured to brackets H before being positioned in frame A, the brackets forming convenient'means for handling the parts thus assembled and for placing them in position within the frame. While in Figs. 1

and 2, onl a half of each pole-face is slot-- ted, the invention is not thus restricted.

In the embodiment of Figs. 3 and 4, the magnets are each formed in one piece. The pole-faces are grooved as shown to receive the outer portion E of the compensating winding E, with commutating pole F extending therethrough. In this instance the compensating coils are shown distributed along the whole pole-face of each magnet.

In the construction shown in Figs. 5 and 6, half of each main pole-face is slotted and the other half plain. The slotted portions N of adjacent or successive magnets are formed of a body of laminated metal 0, of loop or horse-shoe form, which extends within a cavity P in frame A. and secured by screws 0''. Face portions N are slotted to receive the outer coils E of the compensating winding E, the latter embracing the commutating pole F which has a dove-tail and key connection F" with member 0. The non-slotted portions N of the magnets are detachable, bein secured by screw N, portions'N and N dieing embraced by the main field coils C, as shown. In assembling the parts, the integral pole portions N may be projected through the main field coils, the commutating pole F placed in position and the compensating winding inserted, all before said parts are fixed within frame A. The parts thus assembled may then be lifted into position and the removable nonslotted pole portions N passed inwardly through the main field coils C, and all parts made secure by inserting screws N and O. The slotted and unslotted portions of each pole are separated'by a non-magnetic bar R, thus magnetically insulating member 0 from the'outer parts of the machine and reducing the distortion of the main field. In this embodiment of the invention, as in that shown in lFigs. l and 2, the slotted and nonslotted portions of the pole face are so arranged'with reference to the airgap as to maintain uniform or equalized magnetic re sistance.

By referring to Fig. 8 it will be seen that the compensating windings are connected in series with the armature winding, the compensating coils D being in the main circuit S, and the magnet coils C in the shunt circuit T, with the usual field ,rheostat U in the shunt circuit.

lit is characteristic of the several embodiments of the invention that the main magnet frame A is formed in sections which part at A in a lineextending between field magnets unconnected by compensating winding, so that the frame may be taken apart without disturbing any of the hindil'lgS'. I

Tn the drawings, machines with four main poles are shown, but it is obvious that the invention applies to machines with any nuinher of main poles.

While the drawings are executed with particular reference to direct current machines, for alternating current machines the essensame, remembering at the same time that the magnet frame must consist of laminated iron.

\ I claim:

1. A'dynamo electric machine with interpolar air spaces, compensating windings bridging only some of the field pole separating spaces and having a number of ampere turns less than the ampere turns of the armature, the windings extending into only those portions of the pole-faces which are adjacent to the bridged spaces.

2. A dynamo electric machine having only a portion of each field magnet face .slotted with the slotted portions of suctial part of the construction remains the r cessive magnets adjacent each-other and the unslotted portions adjacent each other, and a compensating winding in each alternate magnet-separating space with part of the winding within said'slots,

3. A dynamo electric machine having a compensating winding bridging each alternate field-magnet-separatin space, a portion of each winding exten ing over a part, only of the face of each of said adjacent magnets and a portion of the winding located between the magnets.

4. A dynamo electric machine having a compensating winding extending over only a portion of each field-magnet face, the other portion of the magnet face being so s aced from the rotating part of the ma- -c ine that the reluctance of the air-gap is the same on each portion of the face.

5. A dynamo electric" machine having a compensating winding bridging alternate field-magnetseparat-ing spaces, each winding extendingover only those' ortions of the magnet faces adjacent the brldged space with the winding applied portion and the other portion of'each magnet face so spaced from the rotating part of the machine as to make the reliictance of the air-gap the same oneach ortion.

6. A ynamo electric machine having a compensating winding extending. over only a portionof each field magnet 'face, such face portion being slotted to receive the winding, a ortionof the face a jacent the slotted part being spaced uniformly from the rotating part ofthe machine and the remainder of the unslotted portion diverging from the'rota'ting part, whereby the reluctance of the airgap on the'unslotted portion of the magnet ace is the same as on the slotted portion.

7. In a dynamo electric machine, adjacent field magnets each having a detachable face member, a commutating pole positioned be.

tween the magnets, brackets at opposite sides of said pole connectingthe said facensating winding supmembers, and a com ets with a portion of ported by the brac a portion of each field magnet face I nets adjacent each the unslotted part ofcent field magnets the winding extending into said face memers.

8. A dynamo electric machine having only slotted with the slotted portions of successive magother and the unslotted adjacent .each other, and compensating windings bridging those spaces separating the slotted portions of the-faces with the windings extending into said slots.

' 9. In a dynamo electric machine, a field magnet having a portion of its face recessed and the remainder of the face so spaced from the rotating part of the machine that the reluctance of the air-gap is the same on both the recessed and unrecessed portions of the face, and compensating winding within the face recess.

'10. In a dynamo electric machine, adjacent field magnets each having a detachable face member, supporting members extending across the magnet-separating space with the face members secured therebetween, and a compensating winding extending to the face members.

11. In a dynamo electric machine, adjacent field magnets each having a detachable and slotted face member,- support-ing members extending across the magnet-separating space with the face members secured therebetween, the supporting members being slotted like the time members, and a comensating winding within the slots of the ace and supporting members.

12. In a dynamo-electric, machine, adjaeach having a detachable face member, handle-forming brackets extendin across the magnet-separating space with t e face members secured between the brackets, and a compensating winding extending tothe face members.

portions In testimony whereof I affix my signature 

